Safety devices for fuel outlets to prevent delivery of flammable fuel to a motor vehicle under dangerous conditions are known and have been in use for a number of years. For example, a U.S. Pat. No. 5,329,164 of Saito discloses a fuel supply system for a motor vehicle wherein a solenoid valve is interposed in an air breather pipe by which fuel vaporized in a fuel tank is introduced into a canister, and the solenoid valve is opened by an ON signal of a fuel flap switch which turns on when a fuel flap is opened so as to bring the air breather pipe into communication from the fuel tank to the canister, thereby permitting the fuel tank to be fueled. A safety circuit for a fuel supply system of a motor vehicle comprises a solenoid valve driving circuit which extends from a power source to an earth through the fuel flap switch. The solenoid valve is provided with a first relay of a normally-closed type to turn OFF in an ON state of a boost switch which turns on when a stop of the engine is detected. In an ON state of an ignition key switch an ignition coil driving circuit extends from the power source to the earth through the ignition key switch. An ignition coil is provided with a second relay of normally-closed type to turn OFF during energization of the solenoid valve driving circuit, whereby the fuel tank can be fueled only when the engine is stopped.
Another approach for avoiding delivery of fuel under dangerous conditions is disclosed in a U.S. Pat. No. 6,222,458 of Harris entitled Automatic Cell Phone Detection. At A Combustible Delivery Station, As disclosed, protection against use of a two way radio, e.g. a cellular phone is prevented at a combustible delivery station. One mode is active, and detects operating cell phones at the gas station. The phones can be detected using Bluetooth The pump can be turned off when the alarm is detected. Another mode is passive. This mode can be via shielding, alone or with RE jamming.
A still further approach for avoiding delivery of fuel to a motor vehicle under unsafe conditions is disclosed in a U.S. Patent of Struthers et al for a Fuel Dispenser Having An Internal Catastrophic Protection System, U.S. Pat. No. 6,575,206. As disclosed, a fuel dispenser for service stations comprises an integrated catastrophic protection system. The dispenser comprises a leak detector, an impact (or displacement) sensor, and a heat sensor for detecting dangerous conditions in or around the dispenser. The sensors may be connected to a processor within the dispenser or may send signals to a remote processor. Upon detection of any of the dangerous conditions, a system controller can take appropriate action to shut down part or all of the fuel system in the facility to avoid a fuel catastrophe.
Notwithstanding the above it is presently believed that there is a need for an improved safety device for a fuel outlet commonly referred to as a gas station or the like to prevent pumping fuel such as gasoline or other highly volatile fuel into a motor vehicle while the vehicle's engine is running. There should he a demand because the system in accordance with the invention is located in a gas station and not in each auto. Further, the device has three separate sensors to determine if the vehicle adjacent the pump has an engine that is running. There should be a demand for such systems because the systems in accordance with the present invention are believed to be highly reliable, relatively free of maintenance and capable of being manufactured at a competitive cost. The systems in accordance with the present invention also incorporate an automatic warning for alerting a driver to turn off the vehicle's ignition in order to pump fuel.